Peptide encoding and dual-function sRNAs in Bacillus subtilis

枯草芽孢杆菌是最重要的非致病性革兰氏阳性模式生物，可以将大量的蛋白质分泌到生长介质中，因此被用于工业生产淀粉酶和蛋白酶等多种酶。与革兰氏阴性模式生物大肠杆菌不同，枯草芽孢杆菌具有天然的能力，能够在营养压力下产生孢子，从而在极端条件下生存。此外，由于它与炭疽杆菌或蜡样芽孢杆菌等致病杆菌相关，因此它也可以作为模式生物来调节这些病原菌的代谢反应或应激反应。本项目的主要目的是在枯草杆菌中鉴定新的多肽编码和双重功能的sRNA，并进一步从表达、靶标和生物学作用方面对它们进行表征。我们希望发现由短的mRNAs或新的双重功能的sRNAs编码的小肽的新功能。实验工作将分为以下三个部分：1)四种编码sRNAs的多肽在不同生长和胁迫条件下的表达谱分析和表达调控。潜在转录调节因子的鉴定2)使用C-和N-末端标记的多肽以及野生型、敲除和高表达菌株的转录和多肽的共洗脱和免疫共沉淀分析来寻找多肽靶标。阐明这些多肽的生物学作用。3)利用转录组学和体外和体内相结合的技术研究这些spRNA的额外碱基配对功能

Bacillus subtilis is the most important non-pathogenic Gram-positive model organism that can secrete proteins in large quantities into the growth medium and is, therefore, used for the industrial production of a number of enzymes such as amylases and proteases. In contrast to the Gram- negative model organism E. coli, B. subtilis is naturally competent and can sporulate in response to nutritional stress to survive extreme conditions. Moreover, since it is related to pathogenic Bacilli as e.g. B. anthracis or B. cereus, it can be used as a model organism for the regulation of metabolic responses or stress of such pathogenic bacteria as well.The major aims of this project are to identify novel peptide encoding and dual-function sRNAs in B. subtilis and to further characterize them in terms of their expression, targets and biological role. We expect to discover novel functions for small peptides encoded by either short mRNAs or new dual function sRNAs.The experimental work will be divided into the following three parts:1) Analysis of expression profiles and expression control of four peptide encoding sRNAs under different growth and stress conditions. Identification of potential transcriptional regulators.2) Search for peptide targets using co-elution and co-immunoprecipitation assays with C- and N-terminally tagged peptides and transcriptomics and peptidomics with wild-type, knockout- and overexpression strains. Elucidation of the biological role of these peptides. 3) Investigation of additional base-pairing functions of these spRNAs using transcriptomics and a combination of in vitro and in vivo techniques